Sunday, August 23, 2009

But aren't all terns Elegant?

Obviously, I've got at least one more San Diego post in me. This is a series of tern pics from the same mudflat where the western sandpipers and the large shorebirds were. I'd been photographing the sandpipers for probably 20 minutes before I suddenly realized I'd been hearing tern vocalizations for several minutes and looked up to see my lifer Elegant Terns settling onto the saltmuck.

Elegant tern is well known to have a lot of variability in the bill, though this one definitely emphasizes the long, relatively narrow bill with fairly typical coloration. An article from the San Diego Atlas project notes that an Elegant Tern's bill is about 5 1/2 times as long as it is thick whereas Royal (and Caspian) have bills about 3 - 3 1/2 times as long as they are thick.

The bill heft was probably the most helpful mark for me. The bird on the right, and the front-most of the birds on the left, are clearly Elegants. The juvenile is a Royal Tern. The rear-most bird on the left (I'm pretty sure) is a Royal Tern based on the bill. Once it reaches full winter plumage it will have even less black on the head, currently its crown is fairly comparable to the Elegants:

The pinkish hue to the underparts was also more pronounced than I've seen before in terns (I've never seen a roseate), and is apparently fairly unique amongst the larger terns.

Here's a juvenile. These have a yellower bill than the adults. I think I over-cropped this image for the blog. On the original there's a nicer symmetric X formed by the reflection of the spread wings:

The bird on the right is the one that stimulated me to write this blog as I did a fair amount of reading on the web. I'm sure glad I saw it in San Diego and not at Tiscornia.
I doubt this bird would be accepted as a certain Elegant anywhere but in the core range (and maybe not even there?). There are a number of things that make it a significant outlier from the others that I photographed. The first thing that pops out is the all yellow bill, yellower than the juveniles that I saw, despite being at least a year old given that it has a nearly all-black cap. It's clearly at a different point in its moult than any other Elegant I saw. No other tern had a nearly all-black cap, the rest were all nearly to winter plumage. Furthermore, its mantle and wing coverts are much rattier than the other birds which had very clean plumage. The legs are a different color. If this bird were at Tiscornia (or on the Atlantic Coast), the possibility of Cayenne Tern (from South America) or Lesser Crested Tern (from West Africa) always gets raised on the listservs. However, per Paul et al, 2003, the Cayenne is the size of Sandwich tern, so would be noticeably smaller than the Elegant next to it. Lesser Crested Tern apparently has a gray, not white, rump and tail so I think both birds are ruled out. Monroe, Jr, 1956, reported that by August 14th, 95% of the birds were in complete winter plumage. It doesn't say, though, whether the other 5% are close or if they're way behind like this bird. These photos were taken on August 8th. A gem of a paper from about a hundred years ago describes leg color of Elegant Tern as ranging from sepia to black, usually splotched (especially on the underside of the webbing) with yellow or salmon similar to the bill color. (It also reports that some of the specimens were attracted into shotgun range by repeatedly lobbing an already dead willet into the water. Apparently Elegant Terns don't pay much attention to the typical feeding habits of willets).
My best guess is that this is a one-year-old bird that's for some reason way behind on its moult. I don't have the Olsen and Larsson big tern book or the waterbird Pyle however.

Finally, one last comparison of Royal Tern on the left and Elegant Tern on the right, showing comparison of size, bill shape, and the typical amount of black on the crown.

Since I couldn't get blogger to link directly to papers found in the Sora database, here's the other citations I used:
author unclear. Notes on the Elegant Tern as a Bird of California. Condor: 1920's?
Monroe Jr, BL. Observations of Elegant Terns at San Diego, California. Wilson Bulletin: Vol 68, No. 3, 1956.
Paul, RT, and AF Paul, B Pranty, AB Hodgson, and DJ Powell. Probably hybridization between Elegant Tern and Sandwich Tern in west-central Florida: The first North American nesting record of ELegant Tern away from the Pacific Coast. North American Birds: Vol 57, Num 2, 2003.

Monday, August 17, 2009

Return to the Beach

I had a chance to do some birding locally for the first time since returning from San Diego.

There were two willet on Jean Kloch Beach, an adult on the left and a juvenile on the right.
The juvenile seemed slightly larger than the adult with a thicker bill base. Hayman's Shorebirds says females are slightly larger than males, I didn't see anything regarding this in a quick glance at Karlson's Shorebird Guide or big Sibley.

A beachwalker pushed the birds closer to me, here's the adult with worn plumage and a few all gray winter feathers coming in at the edge of the mantle (in the scapulars)
The juvenile's plumage is much neater as it's much fresher with smaller feathers on average. They're also plainer at the base (especially as you look in the wing coverts) which I suspect is a function of them being rapidly grown.

I spent most of my time sitting near the gull flock hoping that a little gull or rare tern would join the 15 or so Forster's and Commons on the beach. The terns can be a difficult problem in the fall since both species have dark primaries this time of year.

I didn't see much evidence that the Forster's are moulting their primaries yet. The birds fairly consistently had all the primaries fairly dark with a contrasting hoar frost gray streaked into them

The common terns on the other hand frequently had a gray inner primary (though this bird doesn't) and had less of the frosted look to the primaries, they're somewhat more evenly colored.

In some lightings (mainly bright overcast), the Forster's clearly had intensely colored orange legs whereas the Commons had duller red legs. The last photo has 2 Forster's in the background and 3 Common's in the foreground. I couldn't get the two species in the same focal plane to illustrate the somewhat thinner (and possibly shorter) bill of Common.

Finally a quick shot of the 10 turnstones that flew past me, landed, and started sprinting away...

Saturday, August 15, 2009

ID puzzles

The first puzzler is a classic problem, rufous vs Allen's hummingbird. This bird appears to be an adult female given that it has a few red feathers in the center of the gorget. Young males of this group tend to have a few red feathers spreading out laterally per Pyle and suggested by Sibley. Pyle states that hummingbirds may be aged by the presence or absence of corrugations on the surface of the upper mandible of the bill. I don't think any are present, but in looking back at all the hummingbird pics I have in my collection I'm not finding any that show the corrugations.

Unfortunately I never got any shots of the spread tail. This pic is the best I have of the folded tail. If this was a male then I think that the shape of the dark markings might make it more likely to be Allen's; I don't know if the same would apply to females.
Allen's does breed in Southern California, Rufous would be a migrant. I left my Lane SoCal guide in California so I don't have access to the occurrance bar graphs which also might be helpful.
Finally a couple skippers. I think this one is a fiery skipper.

I think this one is an umber skipper, again emphasis on the think.

Thursday, August 13, 2009

California gulls in California

Similar to western sandpiper, most of the California gulls that I've seen have been in places where they're vagrants. On our last night in California we went to Huntington Beach. Honestly the sand at Tiscornia is nicer though obviously the breakers of the Pacific Ocean were more impressive. There was a gull flock of about 50 birds, a mix of Western, California, and Heerman's, so I just panned across it and photographed every bird.

I didn't see any juvenile California gulls. The next several images are second summer birds. Some of them, such as the first bird, would be unlikely to draw the eye in Michigan, especially if they were alone. For the most part though, the young California gulls had a little more brown through the eye, a duller bill, and a longer more tubular bill than a Herring gull would. Most of them look a little smaller headed to me as well.

The next two images are of the California gull I had at Tiscornia in very late May a few years ago. The benefits of studying lots of the birds in places they're supposed to be becomes clear given that at the time I aged (and submitted) it as a bird coming into it's second summer. It's 3rd summer. It's also probably a different subspecies. I can't remember which subspecies has a slightly darker mantle. I think the differences between the apparent mantle shade in these 2 pics as compared to the last ones on this page are due to lighting and camera exposure.

And finally, some adult type birds. Again, they seem to have a little more black through the eye than a Herring gull would. The bill is again longer and with less of a gonydeal angle than a Herring gull's for the most part. The dark eye is also worth noting though I have seen adult Herring gulls with at least one dark eye.

Ignore the primary length of the first bird, it's moulting the outer primaries.

The bill of this last bird does not seem to be as long as the others.

Wednesday, August 12, 2009

Extinct is (mostly) forever

We spent a day and change at the San Diego Zoo where the kids again enjoyed the "amimals."

On the tram ride we went by a condor exhibit. The saga of the California Condor is well known. I was really surprised by their size however. The birds were the length of a hen turkey but appeared to have twice the bulk. I can easily see how condors would have made simple aerial targets for bored hunters (the ones that didn't die of ingested, rather than high velocity, lead poisoning at least).

Andean condors are also apparently endangered, this young one was part of one of their shows and flew right past us.

This is a Guam Rail.
It's in the same situation as the California Condor; extinct in the wild. As a smaller bird I suppose it might be easier to propogate more of them in captivity. I don't know, however, whether there is any social impetus to do this. Given that their natural habitat is still over-run by introduced cats, rats, and snakes, I doubt that these flightless birds could ever be re-introduced.

I know that a re-introduction of captive-raised thick-billed parrots was attempted in the Chiricahua's a decade or so ago. If memory serves, most of these were picked off by great horned owls when they selected exposed perches for roosting. I don't know what the status of the Mexican population is though I'm sure they're threatened at minimum.

I've always thought red-breasted geese were one of the more attractive waterfowl, at least in my mental picture of one. Up close they take on more of a bizarre appearance.

Finally, a member of their menagerie that was not quite so endangered, a (drumroll please) red-breasted merganser.

Tuesday, August 11, 2009

Uppercase Western Gulls

I'm back from California, but have at least a few catch-up posts left. I'm going to focus on Western Gulls in this one.

They're big gulls, heavy-chested, and even heavier billed. The heavy bill was even obvious to the naked eye as they would fly over the highways.

I saw a few juvenile birds at various places, the only juvenile gulls I encountered. The dark brown spangled-edged feathers of the mantle and reasonably neatly checkered wing coverts reminded me somewhat of lesser black-backed (though that bill does anything but).

The second year birds take on more of a herring gull look, with plainer dark plumage; basically big ugly brown things.

Based on the black-tipped yellow bill and the retained brown tertials with marbled white edges (also something that always stands out to me on lesser black-backed) I think this is a 3rd summer bird:

This is probably a 4th summer bird given the remnants of brown on the head and neck, mostly bi-colored yellow bill, but with adult primaries growing in.

Finally the adult birds. Sibley notes that eye color varies between dark in the north and pale clear yellow in the south with there being a perceptible change in central California. I didn't try to grade the ones I saw, but clearly there was some variation in the population based on these 2 photos:

Finally is a probably a member of the Glaucous-winged x Western Gull hybrid swarm sometimes known as "Olympic" Gull so-named for the overlap zone in that part of Washington where virtually all of the birds have mixed parentage. The bird has a paler mantle than a Western Gull and some marbled head and neck patterning far greater than what a Western Gull should have:

Coming soon to a blog near you, the other Western gulls I encountered, Heerman's and California...

Sunday, August 9, 2009

Western sandpipers ... in the West

As I mentioned yesterday, I probably shot 200 images of Western Sandpipers yesterday. I always worry about learning species (i.e. western sand and Ross's goose) strictly in areas where they're semi rare. Whenever I'm staring at a Ross's goose's bill base I always wish I could head off to the Salton Sea to see a thousand of them so I figured I should jump at this opportunity.

SO, for your viewing pleasure, various pics of western sand selected by a random process (the ones that have the best profile of the bill). I believe all are adults, as you can see they vary between just starting to moult into winter plumage to being well on their way. All at this point though, retain at least a few colorful scaps and all have at least a few markings on their flanks.

Somehow I doubt I'm going to get this quality of photo when one shows up at 3 Oaks...

Saturday, August 8, 2009

San Diego Shorebirds

Berrien county is certainly a fun place to bird. However, if there's one drawback often noted (besides winter of course), it's that there's very few respectable mudflats. There's even fewer tidal mudflats. That's not really a problem when birding the San Diego River.

Here's a long-billed curlew from earlier this evening:
And another from yesterday evening:

The whimbrel, while it appears huge at Tiscornia beach has about half the bulk of its larger cousin:

Marbled godwits actually seem much bigger here than they do at Tiscornia, perhaps because they allow closer approach when there's a narrow channel separating it from you. This one finished a prolonged preening session with probably 2 minutes of scratching its chin:

Finally a break from the large shorebird theme of the blog, a black turnstone which appeared out of nowhere foraging past the edge of the mudflat where I was hunkered down. This one was a lifer, and quite away from the rocky ocean-side habitat I expected it:

While this post might not suggest it, I spent the bulk of my birding time this morning photographing Western Sandpipers given that they're back on the Michigan review list and abundant here, but that'll be a post for another time...